Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Chandy–Lamport algorithm
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
==Algorithm== The Chandy–Lamport algorithm works like this: # The observer process (the process taking a snapshot): ## Saves its own local state ## Sends a snapshot request message bearing a snapshot token to all other processes # A process receiving the snapshot token ''for the first time'' on ''any'' message: ## Sends the observer process its own saved state ## Attaches the snapshot token to all subsequent messages (to help propagate the snapshot token) # When a process that has already received the snapshot token receives a message that does not bear the snapshot token, this process will forward that message to the observer process. This message was obviously sent before the snapshot “cut off” (as it does not bear a snapshot token and thus must have come from before the snapshot token was sent out) and needs to be included in the snapshot. From this, the observer builds up a complete snapshot: a saved state for each process and all messages “in the ether” are saved.
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)